1. Project Introduction

2. Research Question

3. Dataset Information

Table 1. Dataset information
Detail Description
Data Source NOAA NCEI Marine Microplastics
Retrieved from https://www.ncei.noaa.gov/products/microplastics
Variables, wrangled Year, Month, Day, Measurement, Unit, Density.Range, Density.Class, Latitude, Longitude
Date Range, wrangled April 28, 1972 - February 21, 2014
Table 2. NOAA NCEI Microplastics data contributors
Citation DOI
1 Barrows et al.2018 https://doi.org/10.1016/j.envpol.2018.02.062
3 Faure et al.2015 https://doi.org/10.1007/s11356-015-4453-3
5 Law et al.2014 https://doi.org/10.1021/es4053076
6 Goldstein et al.2013 https://doi.org/10.1371/journal.pone.0080020
7 Courtene-Jones et al. 2020 https://doi.org/10.1016/j.marpolbul.2020.111092
8 Russell and Webster, 2021 https://doi.org/10.1016/j.marpolbul.2021.112210
9 Law et al.2010 https://doi.org/10.1126/science.1192321
21 Tunnell et al. 2020 https://doi.org/10.1016/j.marpolbul.2019.110794
31 Kanhai et al. 2017 http://dx.doi.org/10.1016/j.marpolbul.2016.12.025
38 Alvarez-Zeferino et al. 2020 https://doi.org/10.1016/j.resconrec.2019.104633
48 McEachern et al. 2019 https://doi.org/10.1016/j.marpolbul.2019.07.068
57 Queiroz et al.2022 https://doi.org/10.1016/j.scitotenv.2022.156259
63 Suaria et al.2020 https://doi.org/10.1016/j.envint.2020.105494
82 Pedrotti et al.2022 http://dx.doi.org/10.1016/j.scitotenv.2022.155958
133 Eriksen et al.2014 https://doi.org/10.1371/journal.pone.0111913
138 de Haan et al.2019 https://doi.org/10.1016/j.marpolbul.2019.01.053
142 Nash et al. 2023 https://doi.org/10.1021/acs.est.2c05926
145 Fulfer and Walsh, 2023 https://doi.org/10.1038/s41598-023-36228-8
176 Eriksen et al.2018 https://doi.org/10.1016/j.envpol.2017.09.058
177 Alfaro-Núñez et al.2021 https://doi.org/10.1038/s41598-021-85939-3
183 de Haan et al.2022 https://doi.org/10.1088/1748-9326/ac5df1
189 Joyce et al. 2022 https://doi.org/10.1016/j.scitotenv.2022.154036
223 Seemungal et al. 2022 https://doi.org/10.1007/s11852-021-00846-z
249 González-Hernández et al. 2020 https://doi.org/10.1016/j.marpolbul.2019.110757
291 Eriksen et al.2013 https://doi.org/10.1016/j.marpolbul.2012.12.021
296 Egger et al.2022 https://doi.org/10.1038/s41598-022-17742-7
300 Egger et al.2020 https://doi.org/10.1088/1748-9326/abbb4f
311 Tanhua et al.2020 https://doi.org/10.1371/journal.pone.0243203
314 Rodrigues et al. 2020 https://doi.org/10.3389/fenvs.2020.582217
414 Egger et al.2021 https://doi.org/10.3389/fmars.2021.626026
427 Rodrigues et al. 2022 https://doi.org/10.3389/fenvs.2022.998513
474 Setiti et al.2021 http://dx.doi.org/10.12681/mms.24899
569 Cruz-Salas et al. 2022 https://doi.org/10.1016/j.rsma.2022.102423
600 Rose and Webber, 2019 https://doi.org/10.1016/j.scitotenv.2019.01.319
2433 Kanhai et al. 2018 https://doi.org/10.1016/j.marpolbul.2018.03.011
2581 Egger et al.2020 https://doi.org/10.1038/s41598-020-64465-8
3239 Suaria et al.2016 https://doi.org/10.1038/srep37551

4. Exploratory Analysis

4.1 Global Data

This is data from entire globe.

4.2 NPSG Data

Distribution of Samples

Samples within the NPSG.

Distribution of Plastics Densities

Samples of different density classes.

Other variables: does the amount of plastic differ with time?

Plastics over Time

Plastics over Time

At first glance, there appears to be an upward trend.

5. Exploratory Analysis

5.1 Variability in sampling methods

Table 1. Occurrences of Various Sampling Methods within Global Dataset
Method Number of Samples
Aluminum bucket 57
AVANI net 18
CTD rosette sampler 6
Day grab 17
Grab sample 1116
Hand picking 5810
Intake seawater pump 131
Manta net 861
Megacorer 90
Metal spoon 76
Neuston net 7207
Petite Ponar benthic grab 36
Plankton net 74
PVC cylinder 370
Remotely operated vehicle 40
Shipek grab sampler 9
Stainless steel spoon 50
Van Dorn sampler 181
Van Veen grab sampler 7
Sampling Method

Sampling Method

Measurements take by each sampling method.

5.2 Plastics and time

Table 2. Generalized Linear Model Analysis
Analysis P-Value
Linear Regression 1.284e-05
Table 3. AIC Analysis, formula = Measurement ~ Year + Month + Latitude + Longitude
Variable AIC
- Longitude 1069.2
no change 1070.6
- Latitude 1071.3
- Month 1076.2
- Year 1090.5

P value is less than significance level of 0.05. AIC suggests Month, Year, and Latitude are explanatory variables.

5.3 Time series

Figure 3. Decomposition of time series

Figure 3. Decomposition of time series

Seasonality removed

Seasonality removed

Table 4. Trend Analyses
Analysis 2-sided P-Value
Seasonal Mann-Kendall 0.11049
Non-Seasonal Mann-Kendall 0.069721

Interpolated values across the years. Time series analysis, there does seem to be seasonality. The trend has a stronger increase in later years.

6. Summary and Conclusions

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